drm/radeon: rework recursive gpu reset handling

Instead of all this humpy pumpy with recursive
mutex (which also fixes only halve of the problem)
move the actual gpu reset out of the fence code,
return -EDEADLK and then reset the gpu in the
calling ioctl function.

v2: Split removal of radeon_mutex into separate patch.
    Return -EAGAIN if reset is successful.

Signed-off-by: Christian König <deathsimple@vodafone.de>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index 24fb0010..02eee4b 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -496,6 +496,16 @@
 	return r;
 }
 
+static int radeon_cs_handle_lockup(struct radeon_device *rdev, int r)
+{
+	if (r == -EDEADLK) {
+		r = radeon_gpu_reset(rdev);
+		if (!r)
+			r = -EAGAIN;
+	}
+	return r;
+}
+
 int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 {
 	struct radeon_device *rdev = dev->dev_private;
@@ -517,6 +527,7 @@
 	if (r) {
 		DRM_ERROR("Failed to initialize parser !\n");
 		radeon_cs_parser_fini(&parser, r);
+		r = radeon_cs_handle_lockup(rdev, r);
 		radeon_mutex_unlock(&rdev->cs_mutex);
 		return r;
 	}
@@ -525,6 +536,7 @@
 		if (r != -ERESTARTSYS)
 			DRM_ERROR("Failed to parse relocation %d!\n", r);
 		radeon_cs_parser_fini(&parser, r);
+		r = radeon_cs_handle_lockup(rdev, r);
 		radeon_mutex_unlock(&rdev->cs_mutex);
 		return r;
 	}
@@ -538,6 +550,7 @@
 	}
 out:
 	radeon_cs_parser_fini(&parser, r);
+	r = radeon_cs_handle_lockup(rdev, r);
 	radeon_mutex_unlock(&rdev->cs_mutex);
 	return r;
 }